Duplicating machine



Feb. 20, 1940' E. K. JOHANSEN DUPLICATING MACHINE Filed Jan. 2'7, 193'. 5 Sheets-Sheet 1 W E W0 w W Q m E oNgy Feb. 20, 1940. E. K. JOHANSEN DUPLICATING MACHINE Filed Jan. 27, 1951' 5 Sheets-Sheet 5 NVENTOIQ.

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5 Sheets-Sheet 4 *k mm E. K. JOHANSEN DUPLICATING MACHINE Filed Jan. 27, 1937 ,Feb. 20, 1940.

Feb. 20, 1940. K JQHANSEN 2,190,988

DUPLICATING MACHINE Filed Jan. 27, 1937 5 Sheets-Sheet 5 W [War AfMo/rcmsen Batented Feb. 20, 1940 UNITED STATES PATENT OFFICE DUPLICATING MACHINE Application January 27, 1937, Serial No. 122,608

11 Claims. (01. Sill-13.5)

The invention relates to improvements in duplicating machines in which the relative movements of a cutting tool and a work piece are controlled by a tracer moving bver the surface of a model or pattern to reproduce the contour of the pattern on the work piece, and it has particular reference to the mechanism and apparatus for controlling such relative movements of the tool and work.

The invention is particularly adapted for use with metal working machines such as milling machines, boring machines, planers, etc., and may be built either as a component part of the machine or as an attachment. Such machines are ordinarily provided with power driven feed mechanism designed toproduce relative traversing movements of the tool and work in a series of parallel straight line paths in which the tool operates to form the surface of the work piece. When equipped for duplicating or reproducing a pattern, the machine is provided with additional power actuated feed mechanism for effecting relative movement of the tool and work toward and from each other. The latter feed mechanism is preferably hydraulically operated under control of a tracer through the medium of a suitable valve actuated by an independently movable tracer arm arranged to coact with a pattern. The various elements of the tracer are mounted on a tracer head or slide, the tracer head and pattern being moved relative to each other in exact synchronism with the movements of the tool and work.

In certain types of machines, the work and pattern are moved toward or from the tool and.

tracer while in other machines, the tool and tracer are moved while the work and pattern are held stationary. The invention is particularly concerned with machines of the latter type and an important object is to provide improved means by which the movements of the tool and tracer may be accurately coordinated and, at the same time, provide the wide range of adjustability between the tool and tracer that is essential for eflicient operation.

More particularly stated, it is an object of the invention to provide an improved geared drive mechanism by which movements of the tool are communicated positively and accurately to the tracer and embodying means of an advantageous character for effectively preventing lost motion between the parts due to backlash in the gears.

Another object is to provide a drive mechanism of the abovegeneral character embodying means for quickly and accurately adjusting the relative positions of the tool and tracer to place them in exactly the desired relation to the work and patwhich is of practical and relatively simple construction and yet extremely accurate and reliable in operation.

A further object is to provide an improved tracer mechanism having means by which the control may bequickly and easily reversed to permit reproduction of patterns either in duplicate or in reverse as desired.

It is also an object of the invention to provide improved electrical control means for duplicating machines whereby the various operations of the machine may be conveniently controlled from a central point through the medium of push buttons or other simple switches.

Other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment illustrated in the accompanying drawings, in which:

Figure l is a general elevational view of a horizontal boring machine equipped with tracer controlled duplicating mechanism embodying the features of the invention.

Fig. 2 is a plan view of the machine shown in Fig. l.

Fig. 3 is a view taken along the line 33- of Fig. 2 showing the mechanism for drivingly connecting the tool support and the tracer slide.

Fig. 4 is a view taken along the line 4-4 01 Fig. 3, showing details of the micrometer adjusting mechanism comprising a part of the connecting mechanism of Fig. 3, on an enlarged scale.

Fig. 5 is a sectional view taken along the line 5-5 of Fig. 4.

Fig. 6 is a longitudinal sectional view of the front portion of the tracer.

Fig. '7 is a longitudinal sectional view of the rear portion of the tracer.

Fig. 8 is a detail sectional view of the tracer arm bearing support.

Fig. 9 is a sectional view of a modified form of the tracer valve and valve control mechanism. Fig. 10 is a detail view of a modified form of the tracer valve control means.

Fig. 11 is a schematic view showing the hydraulic tracer control circuits and the electrical control therefor.

By way of illustration, the invention has been shown and Will be described hereinafter as incorporated in a horizontal boring machine, but it is to be understood that this is not intended as a limitation of the invention to the particular machine disclosed, it being contemplated that various changes and modifications may be made by those skilled in the art to adapt the invention to other types of metal working machines. It will also be understood that various changes in the form, construction and arrangement of the. parts maybe made without departing from the spirit and scope of the invention as expressed in the appended claims,

Referring more particularly to Fig. 1 of the drawings, the machine selected to illustrate the invention comprises an elongated, horizontally disposed bed I. The bed is provided at one end with longitudinal guides or ways 2 on which a work support 3 is adapted to travel. The work support comprises a saddle 4 in direct engagement with the ways 2 for movement along the bed' I, and provided with horizontal transverse guides or ways 5 on which a work table 6 is mounted for movement transversely of the bed. As herein shown, the work table 8 carries a vertically disposed angle plate 1 on which are mounted a work piece 8 and a pattern or model 9, the contour of which latter is to be reproduced on the work piece.

Rigidly mounted at the other end of the bed I is an upstanding column In provided with vertical guides or ways I I on which a. spindle headstock I2 is adapted to travel. The headstock includes a tool support in the form of horizontal spindle l3 projecting on the side adjacent the work support and adapted to carry a cutting tool l4 for operating on the work 8. The rear end of the spindle is operatively connected with a piston l5 operating in a cylinder 16 to which pressure fluid may be introduced selectively to move the spindle and tool toward or from the work.

Suitable power drive means is provided for rotating the tool spindle I3, for feeding the headstock l2 vertically in either direction, and for feeding the work table 6 transversely of the bed in either direction. In addition, a pump l1 (Fig. 11) driven by an electric motor I8 is arranged to supply fiuid under pressure to the cylinder I6 for feeding the tool spindle toward or from the work. As shown in Fig. 1, the pump together with the motor l8 and a suitable fluid reservoir or sump I9 is enclosed in a separate casing 28 adapted to be mounted at a convenient location adjacent the machine.

Upon the headstock I2 is rigidly mounted a bracket 2| having a horizontally disposed, dovetailed slideway 22 (Figs. 2 and 3) in which a slide 23supporting a tracer 24, to be described in detail hereinafter, is mounted for movement parallel to the axis of the spindle I3. The tracer is preferably of the type having a tracer arm 25 mounted for slight universal movement with reference to a head or casing 26 and having a tip 21 shaped substantially like the tool l4 and adapted to engage the surface of the-pattern 9 as the tool operates on the work piece 8. Since the tracer head 26 is rigidly mounted on the headstock, the tracer tip and tool necessarily move together with the headstock and in fixed relation as to distance apart so that they describe a series of parallel paths relative to the work and pattern in the combined vertical movements of the headstock and the traversing movements of the work table.

With tracers of the above type, movements of the tool l4 toward and from the 'work at right angles to the traversing path are controlled in a well known manner by suitable valve means interposed in the hydraulic circuit of the cylinder l6 and adapted to be actuated by the independent movements of the tracer arm 25 incident to the tip 21 encountering either a rise or a depression in the surface of the pattern. Upon such movement of the tool, it is necessary to impart a proportionate movement to the tracer tending to restore the tracer arm to neutral position and maintain the tip 21 in constant,

substantially uniform contact with the pattern. The relative direction of the tracer movement is dependent upon whether the work is to be a duplicate of the model or a reverse copy of the same, in the first instance the tool and tracer moving to exactly the same extent or degree and in the same direction, while in the latter instance the tool and tracer are moved in opposite directions.

To coordinate the movements of the tool and tracer, the tracer slide 23 is arranged to be driven directly from the tool spindle l3 by means of a positive geared driving connection interposed between the slide and spindle. Referring more particularly to Figs. 2 and 3, the driving connection comprises, in the present instance, a shaft 28 journaled in a vertical bearing 29 secured to the headstock l2. A pinion 29 fast on the lower end of the shaft 28 is arranged to mesh with a rack 30 formed on a sleeve 3| adapted to reciprocate with the spindle I3. Thus forward and backward movements of the spindle serve to rotate the shaft 28.

The shaft 28 is disengageably connected with a second shaft 32 in axial alinement with the first mentioned shaft through the medium of a sleeve 38 keyed to the lower shaft and having clutch teeth 34 engageable with complementary teeth on a sleeve 35 on the shaft 32. The sleeve 35 is operatively connected with the shaft 32 through the medium of a micrometer adjusting mechanism 38 by which the angular relation of the shafts may be varied in infinitely small steps as will appear presently. The sleeve 33 is arranged for movement axially to the shaft 28 to engage or disengage the clutch teeth at will, the teeth being disengaged when the machine is to be operated without tracer control. A yieldable detent 31 (Fig. 4) holds the sleeve in clutch engaging position. i

The upper end of the shaft 32 is journaled in a suitable bearing 38 supported in a gear box 39 on the rear end portion of the bracket 2|. Fast on the upper end of the shaft 32 is a bevel gear 40 adapted to mesh with bevel gears 4| and 42 constituting a reversible clutch mechanism for driving a transverse shaft 43 journaled in anti friction bearings 44 supported in the gear box 38. The gears 4| and 42 are formed integrally with or rigidly secured to a sleeve 45 splined to the shaft 43 for movement axially thereof. A pinion 46 fast on the shaft 43 is arranged to mesh with a rack 41 formed on a rod 48 extending rearwardly from the tracer slide 23. Thus the reciprocatory movements of the spindle 13 are communicated to the tracer slide through the shafts 28 and 32 and the gears 40 and 4| or 48 and 42. The movements of the spindle l3 and slide 23 are in the same direction when the gear 40 is meshed with the gear 42 and in opposite directions when the gear 48 is meshed with the gear 4|.

Any suitable means may be employed for shifting of the gears 4| and 42. As herein shown, this means comprises a lever 49 (Fig. 2) pivoted on a bracket 50 formed on the gear box 39. One end of the lever 49 is formed with two legs adapted to straddle the hub of the gear 4|, each leg having a pin 5| engaging in an annular groove 52 formed in the hub of the gear. Thus the gears 4| and 42 may be shifted axially of the shaft 43 to cause one or the other to mesh with the driving gear 40 by rocking the lever 49 about its pivot. A spring 53 secured to a rearward extension of the lever is normally operative to hold the gears 48 and 4| in mesh. A solenoid 54 having its armature 54 suitably secured to the other end of the lever 49 operates when energized to shift the gear assembly and mesh the gear 42 with the driving gear 40 for reverse operation of the machine. This reversing operation may also be effected manually when desired through the medium of a handle 55 constituting an extension of the lever 49.

Referring now to Figs. 4 and 5, the micrometer adjusting mechanism 36 comprises a worm wheel 59 keyed to the lower end of the shaft 32 and rigidly held in place thereon by a set screw 59 disposed opposite the keyway. The worm wheel is enclosed in an annular housing 60 formed integral with or rigidly secured to the sleeve 35. Meshing with the Worm wheel 59 is a worm 6| fast on a transverse shaft 62 journaled in bearings 83 mounted on the housing 69. In the present instance, the bearings 53 are threaded into the housing so that they may be conveniently adjusted to remove, all end play from the shaft 62. The shaft 62 is provided at opposite ends with. hand Wheels 64 by which it may be rotated and, through the action of the worm Bi and worm wheel 59, thus rotate the sleeve 35 relative to the shaft 32. Since the sleeve 35 is drivingly connected with the shaft 28 through the clutch teeth 34, it will be apparent that this operation serves to rotate the shaft 32 relative to the shaft 28. This movement is communicated to the tracer slide in the usual way so that the relative positions of the tracer tip 21 and the tool |4 may be varied accurately in infinitely small steps to accurately position them in desired relationship to the pattern and the work. Accurate adjustment is facilitated by the provision of a graduated scale 65 on the hub of each of the hand wheels 54.

The micrometer adjustment above described may be utilized to advantage in initially setting up the machine as it makes it unnecessary to place the pattern in exactly the same plane as the work piece. After the work and pattern are mounted on the support I, the tool l4 may be advanced into contact with the work independently of the tracer by disengaging the clutch 34. The clutch is then engaged and the tracer tip advanced into contact with the pattern by manipulating the hand wheel 64. When the tracer is to be moved through a considerable distance, this may be done conveniently and rapidly by disengaging the clutch 34 and rotating the entire micrometer mechanism. The clutch 34 is then engaged and the tracer tip is backed away from the pattern by operating the hand wheel 54. The extent of this backward movement determines the depth of the cut taken by the tool l4 in the surface of the work piece.

For precision work it is essential for the tracer to follow-the movements of the tool exactly, as

any lost motion between these parts will necessarily result in inaccurate reproduction. Means is provided in the present instance for eliminating all possibility of such loss of motion by eifectually taking up the play and backlash in the gears, clutch and other parts of the spindle and slide connecting mechanism. To this end, the rod 48 by which the tracer slide 23 is driven, is provided at its rear end with a piston 68 operating in a closed cylinder 91 supported on the bracket 2|. Provision is made for supplying pressure fluid to the rear end of the cylinder through a duct 68 (Figs. 1 and 11) so that when the machine is in operation, the piston is continuously yieldably urged in a direction tending to move the slide 23 and tracer toward the pattern. With this arrangement all backlash in the gears and clutch mechanism is taken up and the tracer and the tool spindle are moved together and in exactly the same degree either in the same or in opposite directions. The forward and backward movement of the tool spindle'and slide are controlled by a tracer mechanism, and while the said tracer mechanism forms the subject matter of my copending application filed June 21, 1937, Serial Number 149,370, the specific construction and operation thereof will be here described so as to convey a complete and clear understanding of the entire mechanism and its associated parts and the operation thereoi'.

Referring therefore to Figs. 6 and '7, the tracer 24 comprises an elongated hollow casing constructed in the present instance in three sections ll, 12 and I3 rigidly secured together to form aunitary tracer head structure. The section ll disposed at the rear end of the assembly constitutes a housing for the tracer valve and to this end is provided with a series of three ports l4, l5 and 16 arranged in a line extending longitudinally of the casing. A fourth port 1'! is located at one side of the port 15 as will be seen by reference to Fig. 2 of the drawings.

Connecting with the port I5 is a duct I8 lead ing from the discharge or pressure side of the pump H as shown in Fig. 11. Ducts I9 and extend from the ports I4 and'l6, respectively, to a reversing valve 8| which, in turn, is connected with opposite ends of the spindle actuating cylinder I6 bydui-ts 8| and 82. A discharge duct or drain 83 extends from the port 1! to the sump l9.

The casing section II is closed at one end by the section 12 and at the other end by an end plate 84, the several parts being rigidly secured together as by bolts 85. As herein shown, the end plate 84 is provided with 8. depending arm 88 constituting a bracket for supporting the casing structure on the slide 23.

Enclosed within the casing II is a cylindrical sleeve 87 formed with accurately spaced, internal circumferential grooves 88, 89 and 90 communicating respectively with the ports 14, I5 and 18 through apertures 88, 89 and 9|) extending through the sleeve. As herein shown, the sleeve 81 is constructed in three parts to facilitate manufacturing within the extremely close limits essential for this type of mechanism. The sleeve is fitted tightly in the casing section H and held rigidly in place against an internal shoulder 9| on the casing wall by an annular member 92 carried on the end of the casing section 12 and disposed so as to abut against the end of the sleeve. With this construction, accurately dimensioned openings for the ports 14,

I5 and I6 are readily obtained with ordinary manufacturing processes.

Communication between the several ports in the casing is controlled by a hollow, cylindrical valve member 93 slidably mounted for endwise movement in the sleeve 81. The valve member, is formed with accurately spaced peripheral grooves 94, 95 and 96 adapted to cooperate with the grooves 88, 89 and in defining passages between the ports. The outermost or end grooves 94 and 96 are provided with apertures 91 communicating with the interior of the member and thus with the discharge port through the .medium of suitable channels 98 formed in. the

casing wall as shown in Fig. 2.

Preferably, the grooves in the member 93 are.

so positioned that, when the member is in intermediate or neutral position as shown in Fig. 7, the openings for the ports I4, I5 and I6 are tightly closed to prevent theflow of pressure fluid through the valve. When the valve member is moved to the right as viewed in the drawings, the groove connects the ports I5 and I4 so as to direct pressure fluid from the duct I8 into the duct I9. At the same time, the port I6 is connected with the port 11 by way of-the groove 96 and apertures 91. Movement of the valve member 93 in the other direction from neutral position connects the port I5 with the port I6 and likewise connects the port I4 with the port 11. Thus, by small movements of the valve member, the ducts I9 and 80 leading to the spindle actuating cylinder I6 may be connected. selectively with the pressure duct I8 or the drain duct 83.

Suitable means is provided for confining the movements of the valve member 93 within predetermined limits. As herein shown, this means comprises an annular member IOI secured to the end of the sleeve 81 adjacent the retaining member 92 by screws I02, the retaining member being slotted as at I03 to accommodate the heads of the screws. The member IN is formed with an accurately dimensioned internal peripheral notch I04 adapted to receive an annular member I05 rigidly secured to the valve member 93. The depth of the slot I04 is greater than the thickness of the member I05, the difference representing the range of movement of the member in. the slot and therefore the range of movement 0 the valve member.

When the machine is in operation, movements of the valve member 93 are controlled by the tracer arm 25, through the medium of a valve actuating member I06 slidably mounted for endwise movement in the casing section I2. In the embodiment shown in Fig. 7 of the drawings,

a push rod IOI slidably supported in a gland I08:

Bearing against the opposite side of the pad I09 is a second push rod II2 slidably supported in a gland II3 mounted on the end plate 84. The rod I I2 extends rearwardly through a tubular extension I I4 of the end plate and through a hollow adjusting screw H5 threading into the same. A

compression spring II6 interposed between the end of the screw 5 and a collar II'I abutting against .a shoulder on the push rod, urges the rod to the left as viewed in Fig. 7 and thus tends to shift the valve member to the left against the action of the spring H0. is of heavier construction than the spring IIII so that the pad I09 is normally held in tight engagement with the push rod I01 and the latter is urged to the left against the actuating member I06. The pressure exerted by the spring H6 may be readily adjusted by turning the screw II5.

The impositive connection between the valve member 93 and the operating elements provided by the construction above described makes it unnecessary to aline the push rod bearings exactly with the bore of the valve member, thus materially simplifying the manufacture and assembly of the parts. The valve member is enabled to move freely without binding and consequently responds more quickly and accurately The spring I I6 to slight movements of the actuating member I06 under the influence of the tracer arm 25.

The valve actuating member I06 is preferably of hollow cylindrical construction and is provided at each end'with a peripheral bearing surface II8 for sliding engagement with the walls of a cylindrical hardened steel bearing member II9 rigidly mounted on the inner end of the tracer arm and a socket I2I supported within and substantially centrally of the actuating member so that the assembled parts occupy a mini-. mum of space and yet provide a relatively long and firm bearing for the same. An annular retaining ring I22 threaded into the open end of the socket and locked in place by ,a suitable lock nut I23 maintains the ball I20 securely in the socket.

The tracer arm 25extends entirely through the tubular casing section I3 which is threaded into the endof thesection I2 and locked in place by a nut I24 to provide a convenient means for adjusting the overall length of the casing structure. Mounted intermediate the ends of the tracer arm adjacent the forward end of the section I3 is a bearing element I25 having a. spherically formed bearing surface I26 adapted to coact with an inclined bearing surface I2I formed within a hollow cylindrical stationary bearing element I28 threaded into the end of the casing section I3. The interior diameter of the element I28 is sufliciently greater than the diameter of the tracer arm and the element I25 so that the arm may be rocked about the pivot provided by the ball and socket joint when pressure is exerted laterally on the tracer tip 21. A nut I29 threaded on the bearing element prevents accidental movement of the element rela-. tive to the casing.

As shown in Fig. 8, the relative positioning of the bearing surfaces I26 and I2I is such that when the tracer arm 25 is rocked about its pivot, the bearing surface I26 rides up on the inclined surface I21 and shifts the tracer arm axially a distance determined by the degree of deflection of the arm. The bearing I25 is normally centered in the bearing I28 by a compression spring I30 enclosed in a cap or guard I3I threaded on the tracer arm and bearing against the end of the element I28. The pressure exerted by the spring on the tracer arm may be varied by rotating the cap and determines the force required to rock the tracer arm out of normal or intermediate position.

, It will be appreciated that the tracer arm may be moved axially as well as laterally by reason of the tip 21 encountering a rise in the surface of the pattern. In either case, the valve actuating member I06 is moved endwise a proportionate amount and acts through the push rod I01 to position the valve member 98. The relative positioning of the several parts is extremely important and these are preferably adjusted so that the valve member 93 may be shifted to its extreme forward operative position by the spring I I6 and push rod II2 when the bearing I26 is exactly centered in the bearing I21 and in engagement therewith. A slight rearward movement of-the tracer arm produced by either axial or lateral pressure of the pattern against the tip 21 serves to shift the valve member to neutral position. Further movement of the tracer arm shifts the valve member to its other operative position in which the hydraulic circuit connections are reversed. Adjustment of the several parts is quickly and accurately effected by rotation of the casing section 13 relative to the section 12 and by rotation of the bearing element I28 relative to the casing section 13.

When the machine is in operation, the tip 21 is held in constant, substantially imiform contact with the surface of the pattern 9. The contact pressure is determined by the adjustment of the springs II 6 and I30. When the tip enters a depression in the pattern, the valve member 93 follows under the influence of the spring I I6 and positions the valve ports so as to produce an appropriate movement of the tool I4. When the tip 21 encounters a rise on the surface of the pattern, the tracer arm is shifted rearwardly to vary the position of the valve member in the reverse direction.

The tool and tracer may be backed away from the work and pattern under manual control when they are to be shifted to new traversing paths. To this end means is provided for moving the valve member 93 to its rearward position independently of the tracer arm. In the embodiment shown in Fig. '1, this means comprises a solenoid I32 supported on a bracket I33 mounted on the end plate 86' of the casing and having its armature I34 operatively connected with the projecting end of the push rod II2. When energized, the solenoid I32 draws the push rod out of engagement with the pad I09 on the valve member whereby the spring H0 is rendered effective to shift the valve member to the right. Upon deenergization of the solenoid, the push rod H2 is shifted back into engagement with the pad I09 by the spring I16 and the valve member is returned to the position determined by the position of the tracer arm.

Fig. 10 shows a modified valve controlling mechanism wherein the push rod is moved out of engagement with the valve member by manually operable means. In this construction, a nut I35 is threaded on the projecting end of the push rod H2 and is locked in place by a second nut I36. The nut I35 constitutes a thrust bearing for engagement with the free end of a crank arm I31 carried by a shaft I38 rotatably supported on a bracket I39 on the end plate 84. A cam I40 fast on a shaft I also jcurnaled in the bracket I39 is arranged to engage the crank arm I31 intermediate its ends. The cam is shaped so that when the shaft I is rotated, crank arm I 31 is rocked between a forward position in which the push rod is disengaged from the arm, to a rearward position in which the push rod is shifted to the right sufficiently to permit the valve member 93 to move to its rearmost position under the influence of the spring IIO.

For rotation of the shaft I, a vertical shaft I42 journaled at its upper end in a bearing I43 mounted on the bracket I39 carries a bevel gear I44 meshing with a bevel gear I45 fast on the shaft I4I. Any suitable means such as a manually operable lever (not shown) may be utilized to rotate the shaft I42. As herein shown, a spring I46 anchored at one end to a pin I41 projecting transversely from shaft I and at the other end to a pin I48 threaded into the end plate 84 acts to normally maintain the low point of the cam I40 in engagement with the arm I31. Thus, the push rod I I2 is normally free to move through its full stroke without interference. When the shaft I is rotated through a quarter turn, cam I40 operates through the arm I31 to shift the push rod and valve member 93 to neutral position. A further quarter turn of the shaft I4I shifts the valve member to its extreme rearward position.

A further modification of the tracer valve 210- tuating mechanism is shown in Fig. 9. In this embodiment, the valve member 93 is moved positively to its rearward position when it is desired to back ti: tool and tracer away from the work and pattern. To this end, the push rod H2 is formed with a reduced inner end portion I49 adapted to extend through a slightly larger aperture I50 in the pad H09 and is loosely clamped thereto by a washer I5I abutting against a shoulder on the rod and a nut I52 threaded on the end of the rod. The nut I52 is turned up sufficiently tight to take up substantially all end play between the rod and the valve member and yet permit lateral shifting .of the parts so that the push rod may readily center itself with respect to thevalve member without causing the member to bind in the sleeve 01.

The push rod I01 is also modified in this instance by the provision of an enlarged hollow end supported on the end plate 84 of the casing structure and its armature I56 is connected by a link I51 with one end of a lever I58 pivotally supported at I59 on the bracket I55.

The other end of the lever I 58 is positioned for engagement with a sleeve I60 slidably supported on the push rod H2 and yieldably connected therewith by a spring I6] interposed between the sleeve and a nut I62 threaded on the outer end of the rod.

The spring I6I is sufllciently stiffso that when the lever I58 is rocked by energization of the solenoid i 54, push rod I I2 is shifted rearwardly against the action of the spring I'I6 until the valve member 93 reaches its limit position. Further movement of the lever shifts the sleeve I60 axially of the push rod againstthe action of the spring I6I. With this construction, the solenoid armature l 56' is enabled to make a iull stroke without necessitating accurate adjustment of such stroke with reference to the stroke of the valve member. A coiled spring I63 connecting between the lever I58 and the bracket I55 withdraws the lever from engagement with the sleeve I68 upon controlling the machine will now be described. Referring to Fig. 11, it will be observed that avalve I65 is interposed in the pressure duct 18 between the pump I1 and the tracer 24. The

valve I65 is biased to a normally closed position and is provided with an operator in the form of a solenoid I66 adapted to be energized by the closure of a switch I61. A similar valve I68 having an operating solenoid I69 connected in multiple with the-solenoid I66 is interposed in the drain duct 83 between the tracer 24 and the sump I9.

The valve I65, when closed, shuts oil the supply of pressure fluid from the tracer and thus terminates tracer control of the tool. Pressure fluid delivered by the pump I 1 is then discharged through a suitable relief valve I65 and returned to the sump I9. The valve I68, which is closed at the same time as the valve I65, preventsdraining of the pressure fluid from the tracer and other elements of the hydraulic system.

The valve controlling switch I61 is adapted when closed to connect a conductor I18 extending from the common terminals of the solenoids I66 and I69 to one side of a current supply line I. The other terminals of the solenoids are connected to the other side of the line I1I1 by a common conductor I12. A push button H13 is provided for closing the switch I61, the switch being opened by the actuation of a companion push button I14. In practice, the push buttons I13 and I14 are designated as Run" and Stop buttons, respectively, and are mounted on a suitable control panel I18 (Fig. 1) within easy reach of the attendant thus providing convenient centralized control of the operation of the I machine.

The reversing valve 8I hereinbefore referred to as interposed between the tracer 24 and the tool spindle actuating cylinder II6 controls the operative effect of the tracer with respect to the tool spindle. This valve comprises a reciprocable valve member or plunger I15 normally biased to the position shown in the drawings by a spring I16. When the valve plunger is in this position, the duct 19 is connected with the duct 8| and the duct 88 is connected with the duct 82. Thus, when the valve member 93 of the tracer is shifted forwardly by a movement of the tracer arm toward the pattern, pressure fluid is directed via. the ducts 18, 88 and 82 into the forward end of the cylinder I6 and the tool spindle is and tool I4 are moved backwardly from the work. Spent pressure fluid is discharged from the rear end of the cylinder through the ducts 8|", 19 and 83 and returned to the sump I9. Thus, the tool and tracer move in opposite directions so that the contour of the pattern is reproduced in reverse on the work piece.

Any suitable means ay be employed for shifting the valve plunge I15 from its'normal position to its alternate position in which the pressure fluid connections to the cylinder I6 are reversed. As herein shown, a solenoid I11 is provided for this purpose and is arranged .to be energized by the closure of a switch I18 over a circuit extending from one side of the line "I, conductor I19, winding of the solenoid I11, conductor I88 and switch I18 to the other side of the line I 1|. The clutch operating solenoid 54 is connected across the conductors I19 and I88 in multiple with the solenoid I 11 so that the drive mechanism for the tracer slide 23 is automatically set' for proper operation simultaneously with the setting of the reversing valve.

The switch I18 is arranged to be closed by actuation of a push button I8I and to be opened by actuation of acompanion push button I82.

I These push buttons may be designated respectively as the Normal and Reverse buttons and are preferably mounted on the control panel adjacent the push buttons I13 and I14 for convenient access by the attendant.

An additional switch I83 operable by a push button I84 designated the Back push button is provided on the control panel for controlling the tracer solenoid. The circuit controlled by this switch is interlocked with the valve operating circuit controlled by the Normal and Reverse switch I18 so that the tracer solenoid cannot be energized when the machine is set for reverse operation and thus cause the tool to be fed toward the work. To this end, the energizing circuit of the tracer solenoid I32 is taken from one side of the line "I through the Normal switch I18, conductor I88, branch conductor I85, "Back switch I83, conductor I86, winding of the solenoid and back to the other side of the line I" over a conductor I81. Thus, damaging of the tool or work by accidental or inadvertent closure of the Back switch I83 is eifectually avoided.

It will be apparent from the foregoing that the invention provides a duplicating machine of improved construction adapted to reproduce a pattern in duplicate or reverse with extreme accuracy. The machine embodies tracer mechanism which is of sturdy and relatively simple construction and yet accurate and sensitive in operation. An eflicient and positively acting gear mechanism is provided for communicating the movements of the tool spindle to the tracer with an entire absence of lost motion between these parts which materially improves the accuracy of reproduction. The machine is arranged for convenient centralized control enabling the attendant to start and stop the machine, change from normal to reverse operation, or back the tool away from the work independently of the tracer .by simply manipulating conveniently located push buttons. Moreover, the controls are effectively interlocked to prevent damage to the tool or work by accidental or inadvertent operation of the control switches.

I claim as my invention:

1. In a metal working machine. in combination, a tool and a tracer mounted in fixed spaced relation as to distance apart, a support on which a work piece and a pattern are mounted in substantially the same spaced relation as said tool and said tracer, means for causing a relative traverse of the work piece by the tool and of the pattern by the tracer in a straight path across the respective surfaces thereof, said tool and said tracer being mounted on individual supports for independent movement toward and from the amopee tively communicating the movements of the tool support to the tracer support to move the tracer toward and from the pattern, and means for taking up the backlash in the gears of said mechanism to prevent lost motion between said supports comprising means operating directly upon and continuously yieldably urging said tracer slide in one direction.

2. In a metal working machine, in combination, a tool and a tracer mounted in fixed spaced relation as to distance apart, a support on which a work piece and a pattern are mounted in substantially the same spaced relation as said tool and said tracer, means for causing a relative traverse of the work piece bythe tool and of the pattern by the tracer in a straight path across the respective surfaces thereof, said tool and said tracer being mounted on individual supports for independent movement toward and from the work and pattern at an angle to the traversing path, hydraulically operated means controlled by the tracer for moving the tool and its support toward and from the work, connecting means interposed between the tool and tracer supports for positively communicating the movements the tool support to the tracer support, and means for preventing lost motion between said supports comprising hydraulically operated means operating directly upon and continuously urging said tracer support toward the pattern independently of said connecting means.

3. In a metal working machine, in combination, a tool and a tracer mounted in fixed spaced relation as to distance apart, a support on which a work piece and a pattern are mounted in substantially the same spaced relation as said tool and said tracer, means for causing a relative traverse of the work piece by the tool and of the pattern by the tracer in a straight path across the respective surfaces thereof, said tool and said tracer being mounted on individual supports for independent movements toward and from the work and pattern at an angle to the traversing path, hydraulically operated means controlled by the tracer for moving the tool and its support toward and from the work, connecting means interposed between the tool and tracer supports for positively communicating the movements of the tool support to the tracer support, and means for taking up any play in said connecting means to enable the supports to move together without lost motion, said means comprising a stationarily mounted cylinder, a piston reciprocable in said cylinder and operatively connected with the tracer support to operate directly thereupon, and means for supplying pressure fluid to one end of the cylinder to continuously yieldably urge said tracer support toward the pattern against the action of said connecting means.

4. In a duplicating machine, in combination, a tool and a tracer mounted on individual supports in fixed spaced relation as to distance apart for cooperating respectively with a work piece and a pattern, said supports being independently movable toward and from the work piece and pattern, power actuated means controlled by the tracer for moving one of said supports, a geared driving connection interposed between the supports for communicating the movements of said one support to the other support, and means operating directly upon and continuously yieldably urging said other support in one direction to take up backlash in the gears of said driving connection and thereby enable the two supports to move together without lost motion.

5. In a duplicating machine, in combination, a tool and a tracer mounted on individual supports in fixed spaced relation as to distance apart for cooperating respectively with a work piece and a pattern, said supports being independently movable toward andfrom the work piece andv pattern, power actuated means controlled by the tracer 'for moving one of said supports, means for communicating the movements of said one support to the other support, and means for preventing lost motion between said supports comprising hydraulic means operating directly upon and continuously yieldably urging said other support in one direction.

6. In a duplicating machine, in combination, a tool and a tracer mounted on individual sup-- ports in fixed spaced relation as to distance apart said one support, and means operating directly.

upon one of said supports for taking up the lost motion in said mechanical means and clutch device to insure movement of said supports in exactly the samedegree.

'7. In a duplicating machine having a tool support and a tracer support mounted for independent movement, power actuated means for moving one support, connecting means interposed between said supports for positively communicating the movements of said one support to the other support, said connecting means including a pair of axially alined shafts having driving connections with the respective supports, and adjustable coupling means operatively connecting said shafts, said coupling means comprising a sleeve member fast on one shaft, a casing member rotatably mounted on the other shaft and having a driving connection with said sleeve member, a worm wheel keyed to said other shaft and enclosed within said casing, a worm mounted on said casing and adapted to engage said worm wheel thereby providing a driving connection between the casing and said other shaft, and means for operating said vworm to rotate said worm wheel and said other shaft relative to said one shaft to vary the relative positions of said supports.

8. In a duplicating machine, in combination, a cutting tool, hydraulically operated means for moving it toward and from a work piece/a tracer adapted to cooperate with a pattern as the tool operates on the work piece, valve means operable by said tracer for controlling the supply of pressure fluid to said hydraulically operated means to vary the position of said tool relative to the work piece, said valve comprising a valve member movable from a neutral position into either of two operative positions effective respectively to cause the tool to be moved toward and from the work piece, means for reversing the operative effect of said valve member with respect to said hydraulically operated means, a solenoid adapted 8 2,190,0as when energized to move said valve member to one operative position independently of the tracer, and means for maintaining the said solenoid against energization when said reversing means is operated.

9. In a duplicating machine, in combination, a tool and tracer mounted on individual supports in fixed spaced relation as to distance apart for cooperating with a work piece and a pattern, said supports being mounted for independent movement toward and from the work and pattern respectively, power actuated means for moving the tool support toward and from the work, mechanical means including a reversible clutch device connecting said supports operative to move the tracer support simultaneously with and in either the same or opposite directions to the movement of said tool support, control means operated by said tracer for controlling said power actuated means to determine the direction and extent of movement of the tool support, reversing means interposed between said control means and said power actuated means the tool support toward and from the work, mechanical connecting means including a reversible clutch device connecting said supports operative to move the tracer support simultaneously with and in either the same or opposite directions to the movements of said tool support, valve means operable by the tracer for controlling the supply of pressure fluid to said hydraulic means to determine the direction and extent of movement of the tool support, a reversing valve interposed between said valve means and said hydraulic means for reversing the operative eflfect of said valve means on said hydraulic means, and electrically operated means for simultaneously operating said reversing valve and said clutch device to properly coordinate the movements of the tool and tracer.

11. In a duplicating machine, a cutting tool slide, a tracer slide carrying a tracer, said tracer adapted to follow the contour of a pattern, a positive and operative connection between the tool and tracer slides, whereby the movement of one toward and away from its operating plane will EINAR K. JOHANSEN, 

